Tray stacker



J. S. HARDY TRAY STACKER Sept. 17, 1946.

Filed May 19, 1944 s Sheets-Sheet 2 INVENTOR JS 5. Hardy ATTORN 5Y5 Sept. 17, 1946. ARDY 2,407,782

TRAY STACKER Filed May 19, 1944 s Sheets-Sheet 3' Y INVENTOR J. S. Hardy BY? I Huul/ ATTO RN EYS Patented Sept. 17 1946 OFFICE 2,407,732 TRAY STACKER John s. 'Hardy,'L0's Gatos, Calif.

Application May 19, 1944, Serial No. 536,337.

1 Claim. 1

This invention is directedlto, and it is anpbject to provide, a novel power actuated tray stacker; the invention being especially designed to receive fruit or vegetable drying trays at a predetermined convenient point, to elevate and advance the trays while maintainin the same horizontal, and then, while continuing to hold thetrays horizontal, to lower them onto a dehydrator truck or the like in a symmetrical stack.

An additional object of this invention is to provide a tray stacker, as above, which includes a pair of vertically mounted endless conveyors disposed in transversely spaced facing relation and on the runs of which conveyors tray-supporting units, for conveying and depositing the trays, are turnably attached in spaced, matching position; the matching tray supporting units on corresponding runs of the conveyors being adapted to engage under opposite ends of a tray, and means cooperating with said units to rotatably control the same whereby to maintain the trays horizontal through their entire path of movement.

A further object of the invention is to produce a simple and inexpensive device, and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claim. r

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is an end elevation, foreshortened, of the tray stacker viewed from the outlet end.

Figure 2 is a sectional elevation of. the tray stacker.

Figure 3 is an enlarged fragmentary end view of one of the tray supporting units and its control mechanism.

Figure 4 is a fragmentary plan view of one of the tray supporting units and its control mechanism. 7

Referring now more particularly to the characters of reference on the drawings, the improved tray stacker comprises an upstanding skeleton frame of substantial height which includes, adjacent the corners thereof, vertical posts I connected at their upper ends by top beams 2. This frame is preferably supported at its lower end in a pit 3. Transversely spaced truck support ing rails 4 extend across the pit centrally be tween the sides of the frame and said rails may be extended directly from the tray stacker to a 2 dehydrator. For the purpose of receiving loaded drying trays, a truck 5 is supported on rails 4 in the position shown in Fig. 2. a

The tray stacking mechanism is supported-in the above frame and comprises, on each side of the rails 4 and path of truck 5, a pair of vertically disposed, transversely spaced endless chains 6 which extend at their upper and lower ends about longitudinally spaced, horizontally alined sprockets 1 whereby the side runs of said chains are vertical and the end runs horizontal,

as shown. The endless chains 6 are supported at opposite ends by shafts suitably journaled in the frame, the uppermost shafts bein indicated at 8, and comprising the means by which the chains 8 are driven at equal and constant speed.

. Each pair of the endless chains 6 is provided,

at equally spaced points along the length thereof, with tray supporting and conveying units, indicated generally at 9; the units of the respective pairs of chains 6 being disposed, in alinement whereby said units travel in cooperative tray supporting relation to each other.

The units 9 are each of identical construction, and therefore a description of one will sufiice. Each tray supporting unit comprises a shaft l0 extending between and turnably mounted in connection with the endless chains 6, which together form a conveyor for the tray supporting units and trays thereon. The shaft [0 of each unit is disposed parallel to the conveyor axis and projects at the ends beyond the corresponding chain. At its inner end the shaft H1 i provided with a, fixed head II which carries an elongated cross member I2; the head ll being disposed centrally between the ends of said cross member. Adjacent its ends the cross member supports pivotally mounted, laterally swingable shoes l3 which include upwardly facing shoulders M which extend laterally inwardly from back stops I5. The shoes I3 are normally urged laterally inwardly to the position shown in full lines in Fig. 3 by means of a torsion sprin l6; such shoes being yieldable outwardl however, to the position shown in dotted line in Fig. 3. Below the shoulder l4 each shoe includes an outwardly and downwardly diverging face IT.

The shafts ll) of the tray-supporting units 9 are turnably controlled, by the following mechanism, in order to maintain the cross members [2, together with supported trays, horizontal at all times during movement of said trays between a loading position and stacked position, as hereinafter described:

This mechanism comprises, for each tray supoffset upwardly relative to the sprockets I a distance approximately the length of the control rods l8. Thus, while the upper and horizontal runs of the chains [9 are parallel tocorresponding runs of the chains 6, they are nevertheless spaced vertically thereabove.

The control rods I8 adjacent. their upper ends slidably engage through blocks 2| carried on turnable cross pins 22 attached to the adjacent and corresponding chain "I9. The supporting sprockets for the chains I9 are carried on frame mounted shafts, the uppermost ones of which are indicatedat 23; the chains l9 being driven in the same direction and at the same speed 'as thechains "6.

"Thus, when the tray supporting units are in the vertical runs of the chainsB, the control rods #8 are likewise vertical, holding said units and "supported trays in horizontal position. As the tray supporting units pass with the chains 6 about the sprockets l at either end of the device said units, together with the supported trays, 'are still maintained horizontal, for the reason that'thecontrol rods 18 are maintained vertical due to the vertical offsetting of endless chains [9 relative to chains 6. This "produces the desired relative rotation of the shafts It! as the chains B pass from the vertical runs to the horizontal end runs thereof.

The means for driving the chains 6 and 19 at a constant and equalspeed comprises an electric motor 24 connected by a chain drive 25 with the lowermost shaft "26 of one of the sprockets 20. The shafts 23 for the uppermost sprockets "20 are-connected in-driving relation by means of a countershaft '21 at the top of the frame and endless chains 2'8 on oppositeends of said countershaft. In addition, shafts '8 of the upperm0st'sprockets 'l are driven from corresponding shafts 23 bymeans'of other endless chains 29.

In use of the above described tray staoker,'the truck 5 is disposed between the downwardly moving-runs of adjacent chains 6 and withsaid runs in avertical plane centrally between the end 'of said truck. Trays 30 are then manually placed, one at a time, on a supporting bed -3l which is disposed horizontally between the upwardly moving runs of said adjacent chains 6; the bed being formed so that the upwardly moving-shoes 13. of each =tray supporting unit clear said bed.

As the tray supporting units 9 move upwardly the spaced'shoes l3 of corresponding ones of said units 9 engage beneath opposite end portions of trays an, as successively placed upon the bed 3!. Each of the shoes 13 supports the tray on the shoulder l4 and in correctposition transversely "of-the device'by virtueof the'back stop [5.

As thus supported by corresponding units 9 each tray is elevated to a point adjacent the upper end of the device, conveyed forwardly a predetermined distance and then lowered; the trays being maintained horizontal, as previously explained, during their entire path of movement. As the trays lower they are deposited as a symmetrical stack 32 on the truck 5. The .shoes .13 escapefrom the traysas they reach the stack by :reason 0f the fact tthatj'the divergent faces I! of said shoes engage the sides of the stack and are swung laterally to the position shown in dotted lines in Fig. 3. With continued lowering movement of the units 9 the shoes 13 ride down the outside of the stack 32 until they pass onto skirts 33 which extend along- -sideand toa point below the truck 5. When said shoes escape said skirts 33 they are returned by the springs 16 to normal tray engaging position. Vertical guides 34 are framesupported in "transverse alinement andserve to assure that'the trays are deposited on the stack- 32 in substantially correct alinement lengthwise of the device.

After a full stack 32 is formed'on the truck 5, the stacking device is stopped and the truck, together with the stack thereon, is run" on the rails l directly "to the dehydrator, and another empty'truck is positioned in the stacking device.

From the foregoing description it will be readily seen that I have produced such a device'a's substantially fulfills 'the objects of the invention'as set forth herein.

'While this specification sets forth in detail the present and preferred consti'liction of the "device, still in practice such deviations from such detail may beresorted to as do not form a departure "from the spirit of the invention, as defined by the appended claim.

Having thus described my invention, what I claim as new and useful and desire to secureiby Letters Patent is:

A tray stacked assembly including in combination: two'parallel frame elements spaced apart, a'track passing between said frame elements and from side to side thereof in a horizontal plane above the lower ends of the, frame elements, trucks adapted to be-moved'along the track, a tray station at one side of the frame elements at a point above the *top level of the trucks, an endless chain movable around each frame element, tray-engagingelements on the chains .yieldably projecting into the'space'between the frame elements and adapted to pick trays from said station -and carrythem over the frame elements and deliver them onto a -truck standing on the side of 'theframe elements opposite that side on which the tray station is located, a pair of'plates, such plates being spaced apart and one plate lying on each side ofthe track, such plates being of a height not less than the height of a truck on the track, the .tray engaging elements being adapted to engage the plates and to be thereby deflected away from .any truck standing on the track between the frame elements as such tray engaging elements .move around the lower ends of the frame elements.

J OHN' S. "HARDY. 

